Well, it's not that cut and dried in my experience.
I fly the P-47D. There are quite a few planes that fit those two bills in comparison to what I fly. However, the P-47 has fantastic diving speed. Now it's not a good accelerator compared to most everything else in the plane set, but it dives well at high speed. Lets compare with a Spit IX. The Spit a very high critical mach and has a high compression limit. It gets sluggish due to high control forces at high speed, but with trim you can control it to very high speeds. I can still out-dive a Spit IX if I do a couple of things. First, use a 0G extension. Second, have enough separation to keep him from getting guns on until I can get to high speed.
Now by a 0G extension I mean dive in a downward arc and keep the G meter at 0 G's until you are either going pretty damn fast or you don't want to go to a steeper angle. If we start from a very slow speed, like 180 Mph, the Spit will out-accelerate me and catch me at first, so I need some separation to stay out of the way. However, as the speed increases over about 350, the Jug's diving ability will kick in and I will leave just about anything in the game eating my exhaust. I can level the Jug out at 500 Mph and cruise home. Now, if the Spit pilot is smart, he can "cut the angle" by diving at a more shallow angle and hoping to catch me as my speed drops off after I level out. There are two problems for the Spit driver in this case, one being that I can get a LONG way before he gets me, and the second being that my kite will hold it's speed better going fast than his will. So maybe he catches me, and maybe not. Either way I have gained enough separation to either reach a friendly area or reverse and blast him in the face if he is closing.
However, generally speaking, you are correct. You don't want to try diving away from a great accelerating plane like the 109-G10 unless you have a lot of separation or are quite fast to begin with. If you can get far enough away, the G10's low compression speed will allow you to escape.
My worst enemies in this regard are the F4U and the P51. Both of those planes are faster on the deck and dive very well. I have to be VERY careful around these enemy planes, as I can't necessarily pull my normal 500 MPH-hair on fire-screaming like a girl on the radio-escape move and live.
Sometimes I can get away with it anyway. Remember that if you get VERY close to the ground your icon range decreases to 3.0 I think. In addition, if there are other friendlies in the area, the enemy won't be as eager to dive to follow you. So even if you can't be sure of an escape, many times you can use visibility and other threats to cover your escape. It doesn't take very long to check out of the area in a Jug at 50 feet doing 550 Mph. <G> If you can distract the enemy for a few seconds by the time he looks back you can be a spec that is rapidly vanishing.
What plane do you normally fly? We can discuss the planes you need to be carful of and maybe some of the attributes of that plane you can use to escape if you like.
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Lephturn - Chief Trainer
A member of The Flying Pigs
http://www.flyingpigs.com "A pig is a jolly companion, Boar, sow, barrow, or gilt --
A pig is a pal, who'll boost your morale, Though mountains may topple and tilt.
When they've blackballed, bamboozled, and burned you, When they've turned on you, Tory and Whig,
Though you may be thrown over by Tabby and Rover, You'll never go wrong with a pig, a pig,
You'll never go wrong with a pig!" -- Thomas Pynchon, "Gravity's Rainbow"